Upright electric roasters and smokers heretofore known in the art have typically comprised: an upright rectangular box having a front access door; an electrical heating element in the bottom of the upright box; a water pan positionable in the box above the heating element; a tray or pan below or above the water pan for holding wood chips or wood pellets for producing smoke; a plurality of food support racks spaced above the heating element and water pan; an air intake port typically centered in the bottom of the box; and a single vent opening in the top of the box. Some units have also included cooking temperature controllers for sensing the temperature of the air or of the food product within the box and controlling the temperature by adjusting the energy output of the electrical heating element.
Unfortunately, the prior art upright electrical roasting and smoking box units have had various significant shortcomings and deficiencies. Because of the direct venting of the hot gas from the top of the box, the thermal efficiency of the prior art electric roasters and smokers has been relatively low. In addition, the direct venting of the hot air from the top of the box also creates a relatively high level of convective air flow through the unit which dries the food product and quickly carries the moisture out of the roasting/smoking chamber.
To reduce the amount of heat loss from the prior art upright unit and to improve its thermal efficiency, a layer of insulation has often been provided between the interior wall and an outer wall of the upright rectangular box. However, the addition of an insulation layer is costly and makes the manufacturing process significantly more complex. Further, in order to protect the insulating material from damage, the maximum roasting and/or smoking temperature of a typical prior art box unit has been limited to such a degree that the unit could only be used for slow roasting and smoking. Because of the inefficiency of the prior art electrical box units and the need to protect the insulating layer from heat damage, the prior art units have typically been only able to operate at a maximum roasting and/or smoking temperature of about 275° F.
In addition, the use of a water pan in the prior art upright electrical roaster and smoker has been necessary in order to counteract the product moisture losses caused by convective drying and rapid air discharge. The need to fill and install the water pan and then remove and empty the pan after use creates a safety hazard (e.g., from hot water burns) and complicates the roasting and smoking process. Moreover, the necessity of using a water pan in the prior art unit is also disadvantageous in that (a) the water pan takes up valuable space within the upright box, (b) a significant amount of energy is required in the prior art unit simply to heat the water to the desired operating temperature, and (c) when the unit is operated at a temperature of 212° F. or above the water in the water pan boils and can produce so much water vapor that the amount of condensate and carbon particles which deposit on the product can be too great to allow the smoke to penetrate the product properly.